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Ctrl-Break
The Break key (or the symbol ⎉) of a computer keyboard refers to breaking a telegraph circuit and originated with 19th century practice. In modern usage, the key has no well-defined purpose, but while this is the case, it can be used by software for miscellaneous tasks, such as to switch between multiple login sessions, to terminate a program, or to interrupt a modem connection. Because the break function is usually combined with the pause function on one key since the introduction of the IBM Model M 101-key keyboard in 1985, the Break key is also called the Pause key. It can be used to pause some computer games. History A standard telegraph circuit connects all the keys, sounders and batteries in a single series loop. Thus the sounders actuate only when both keys are down (closed, also known as " marking" — after the ink marks made on paper tape by early printing telegraphs). So the receiving operator has to hold their key down or close a built-in shorting switch in o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BIOS Call
BIOS interrupt calls are a facility that operating systems and application programs use to invoke the facilities of the Basic Input/Output System firmware on IBM PC compatible computers. Traditionally, BIOS calls are mainly used by DOS programs and some other software such as boot loaders (including, mostly historically, relatively simple application software that boots directly and runs without an operating system—especially game software). BIOS runs in the real address mode (Real Mode) of the x86 CPU, so programs that call BIOS either must also run in real mode or must switch from protected mode to real mode before calling BIOS and then switching back again. For this reason, modern operating systems that use the CPU in Protected mode or Long mode generally do not use the BIOS interrupt calls to support system functions, although they use the BIOS interrupt calls to probe and initialize hardware during booting. Real mode has the 1MB memory limitation, modern boot loaders (e. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
